ORLANDO, Fla. (AP) — Investigators trying to find out what motivated nightclub killer Omar Mateen are casting a wide net.

The FBI is checking reports that Mateen frequented a gay dance club in Orlando before going on a murderous rampage there. Investigators also are looking at whether his wife knew anything beforehand about the deadliest mass shooting in modern US history. The attack left Mateen and 49 victims dead.

On Tuesday, a U.S. official said the FBI was looking into news reports quoting patrons of Pulse as saying Mateen frequented the nightspot and reached out to men on gay dating apps. The official wasn’t authorized to discuss the investigation and spoke on condition of anonymity.

President Barack Obama said investigators had no information to suggest a foreign terrorist group directed the attack.